1. Field of the Invention
The present invention relates to a cartridge for two individual, standard lock devices, collectively referred to as a lockset, utilized on a door panel in connection with the door frame. The cartridge inter-engages with the spindle of the individual locks to join the lock devices together. The device is arranged to be easily installed with unchanged standard lock mechanisms. The cartridge is so constructed as to operate smoothly and reliably.
2. Description of Related Art
U.S. Pat. No. 4,129,019, issued to Urdal on Dec. 12, 1978, discloses a cartridge for a lockset which comprises a first and a second cartridge plates having edge flanges thereon, a rocker lever, a slide, a rotary lever and a lever arm included with the rotary lever. The cartridge plates are directly to each other and are spaced apart by the edge flanges to provide a predetermined space therebetween. It is important that there is a sufficiently smooth movement of the slide with respect to the cartridge plates. This is achieved, according to the Urdal patent, by providing both rounded shoes or bevels on the slide and embossed bearing discs on each cartridge plate. However, the rounded shoes or bevels of the slide in cooperation with the edge flanges of the cartridge plates may produce some slight distortion about an axis of a general plane of the cartridge plates in operation. The situation of distortion is present particularly in view of the fact that the rocker lever uses one of its horizontally extending lever arms to abut and move a corresponding primary lug of the slide at a bottom rightmost or leftmost portion thereof.
Another problem associated with this prior design is that the spaced-apart distance between the first and second cartridge plates as maintained by the edge flanges is not constant. For example, a tightening force for fastening the cartridge plates together may readily and easily change the spaced-apart distance which in turn adversely affects the operating situation of the slide situated and to be moved within the spaced-apart distance.